Troubleshooting Guide
This section discusses potential symptoms, possible causes, and actions for their resolution. Should this trouble-
shooting guide fail to address the symptoms evident in a particular N-20P, please contact Nellcor Technical
Services Department or a local Nellcor representative for assistance.
If the N-20P does not perform as expected:
•
Check for proper sensor placement
•
Depending on concentration, indocyanine green, methylene blue, and other intravascular dyes may affect the
accuracy of a measurement.
•
These instruments are calibrated to read oxygen saturation of functional arterial hemoglobin (saturation of
hemoglobin functionally capable of transporting oxygen in the arteries), significant levels of dysfunctional
hemoglobins such as carboxyhemoglobin or methemoglobin may affect the accuracy of a measurement.
If the electronics and/or display functions require testing, refer to "Test and Calibration" in this manual.
____________
SYMPTOM 1:
No response to measure button.
CAUSE 1:
Battery access door may not be properly latched.
ACTION 1:
Check access door and ensure it is properly latched.
CAUSE 2:
Batteries may be discharged.
ACTION 2:
Exchange them for a new set.
CAUSE 3:
Batteries may be incorrectly installed.
ACTION 3:
Ensure that batteries are oriented according to the polarity indicator.
CAUSE 4:
Batteries may not be making proper electrical contact.
ACTION 4:
Inspect contacts for deformity; clean contacts to remove oxidation.
CAUSE 5:
Fuse F1 on the auxiliary PCB may be open.
ACTION 5:
See "Fuse Replacement"
CAUSE 6:
Dust may have accumulated under measure button causing loss of electrical contact.
ACTION 6:
Clean contact points under measure button (see "Disassembly Procedure").
____________
SYMPTOM 2:
Pulse Search indicator appears for more than 5-10 seconds.
CAUSE 1:
Sensor may be improperly positioned.
ACTION 1:
Ensure the sensor is correctly applied (see sensor directions for use).
CAUSE 2:
Incorrect sensor may be in use.
ACTION 2:
See sensor directions for use to ensure that the patient's weight and sensor application
are correct. Test the sensor on another person to verify proper operation.
12-32